1. Technical Field
The present invention is related generally to magnetic back up and recovery systems and specifically to a tape drive having redundant read and write gaps.
2. Background Art
Digital data tape recorders for backing up and restoring data in a computer system have been in use for many years. Such systems back up data in either a write only mode or a read while write mode. The read while write mode permits virtually instantaneous verification of recorded data while the write only mode typically requires the integrity of data to be verified by reading the tape after completion of a back up or write operation. The write only mode requires only a single write gap and a single read gap or in some instances a single head having read and write capability. The read while write mode requires a storage device having a read gap which trails a write gap relative to the direction of tape movement. Generally, only a single read gap is required for restoring data.
A significant problem with known magnetic storage devices is that in the event of a failure of a read or write gap used during a read or write operation, the storage device controller declares a hardware failure and the read or write operation is terminated without completion. This can be a significant problem when scheduled back ups or restores cannot be completed resulting in delays in using or perhaps even breakdowns in a computer system.
The present invention is directed to overcoming one or more of the problems discussed above.